Vertical Illuminance - Erco

The wall lighting in the
indoor area is continued
outside: the grazing
lighting on the wall and
the illuminated wall of
trees both add to the
emotive ambience on
the terrace.
Designing vertical illuminance
External areas
The lens wallwasher’s
asymmetrical light distribution
is ideally suited
to facade lighting.
The light distribution
avoids spill light straying
upwards, enabling
“Dark Sky” lighting
solutions to be implemented.
Nocturnal facade lighting presents cities, local
authority districts and private clients with a
multitude of design possibilities for lighting
both individual buildings as well as groups
of buildings in the context of public squares,
courtyards or main roads. The spectrum ranges
from simple lighting intended primarily
to provide orientation and safety, through to
presentational lighting solutions and scenic
illumination for special occasions. For buildings
that are visible from afar, such as skyscrapers
or towers, vertical lighting has the
important task of highlighting nocturnal landmarks.
Where buildings around the edge of
public squares are concerned, facade lighting
helps to ensure that these buildings are recognisable
after dark and promotes better spatial
understanding.
In the interest of a “Dark Sky”, the lighting
designer can effectively avoid what is known
as light pollution (i.e. light which is emitted
directly into the night sky) by using highquality
lighting technology and by arranging
the luminaries appropriately.
The texture of basreliefs
on facades and
of other material features
can be enhanced
by the shadow effect
of wallwashing.
Many monuments and historical buildings tell
their story in bas-reliefs, ornamentation or
sculptural decoration. It is only with light and
shadow that the three-dimensional nature
and texture of the surfaces can be appreciated.
Architectural details such as the constituency
of materials, joints or facade patterns
are also amongst those important features
which, when discernable, will characterise the
appearance of a building or structure at night.
The contrast on the surface can be influenced
by the direction of the light and the
type of luminaire. Moving a floodlight further
away from the facade gives the surface a uniform
but flat appearance because the formation
of shadows is reduced. Conversely, luminaires
positioned right next to the facade will
produce extreme shadow, creating a dramatic
impression. A mid-way position, as is the norm
for wallwashers, gives a balanced appearance
with an even light distribution on the surface,
while still allowing the three-dimensional
nature of any details to be easy to recognise.
Correction filters alter the colour impression
for certain ranges of colour only. Thus,
for instance, the warmer tone of the Skintone
filter can emphasise the colour of beige sandstone.
When using coloured light, a nocturnal
perception and atmosphere is created which
is distinct and independent from the daytime
appearance. Certain moods and contrasts can
be created with coloured light, and these can
be used for instance to delineate large facade
surfaces or to distinguish different parts of a
building from each other.
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